Water level build-up in hydrocarbon storage tanks is an unfortunate and inevitable side effect in oil production. In order to avoid sending this unwanted byproduct to downstream refineries, operators manually discharge the water from the storage tank using drain lines. However, this task requires large amounts of man-power, which prevents the operators from focusing on more important tasks, as well as placing the operators at risk of injury or exposure to chemicals. In addition, failure to adequately drain water from the hydrocarbon tanks can cause processing issues for subsequent refineries.
Automatic tank dewatering apparatuses have been introduced; however, they suffer from serious drawbacks such as: requiring major modifications in the tank or the drain piping for installation, requiring frequent calibration and/or maintenance, running the risk of service buildup on the sensors/transducers, and having high costs to implement. FIG. 1 represents an example of automatic tank dewatering apparatuses of the prior art. Dewatering tank 10 has first probe 12 and second probe 14 that are disposed on the inside of dewatering tank 10 so that probes 12, 14 can sense what type of fluid is at certain depths of dewatering tank 10. First probe 12 monitors water concentrations at or neat the bottom of dewatering tank 10. When concentrations reach a predetermined level, first probe 12 triggers the opening of controllable valve 16 on drain line 18. When water concentrations begin to decrease due to drainage, first probe 12 triggers the closing of controllable valve 16. In the event that first probe 12 fails to trigger the closing of controllable valve 16, second probe 14 will trigger both an alarm (not shown) and the closing of controllable valve 16. However, automatic dewatering tanks in accordance with FIG. 1 suffer from expensive installation and require shutdowns in the event of installation, maintenance, calibration, or failure.
Therefore, it would be beneficial to provide a method and an automatic tank dewatering apparatus that was easy to install, did not require frequent calibration or maintenance, was non-invasive, and had a relatively low cost to implement and operate.